Bearing assemblies are typically separate, independent assemblies that are mounted to components to be rotated. FIGS. 1A-1C illustrate a perspective view, side view and cross-sectional view of a conventional thrust bearing 10 in the form of a duplex-pair bearing and includes, for example, an outer portion 12 having a first diameter, and an inner portion 14 having a second (smaller) diameter. The outer portion 12 may be coupled to a first object (e.g., a hub) while the inner portion 14 may be coupled to a second object (e.g., an axle spindle) to enable relative rotation between the first and second objects.
Arranged within the bearing assembly 10 is a first roller element set 16 and a second roller element set 18, each roller element set 16 and 18 including a plurality of roller elements 20 circumferentially spaced apart from one another between the outer portion 12 and the inner portion 14. Each roller element set may include a cage 22 for maintaining the circumferential spacing between adjacent roller elements 20. Each roller element 20 of the roller element sets 16 and 18 ride on an outer race 24 (which is adjacent to the outer part 12) and an inner race 26 (which is adjacent to the inner part 14). The outer and inner races 24 and 26 are configured to correspond to a diameter of the roller elements 20. A rolling surface of the inner race 26 may be axially offset 28 from a rolling surface of the outer race 24 to provide axial stiffness in one direction. By opposing the offset between the first roller element set 16 and the second roller element set 18, axial stiffness in both directions can be achieved.
While conventional thrust bearings provide a satisfactory means for rotating one object relative to another while providing axial stiffness, in applications requiring compact profiles such bearings can become a limiting factor as they can occupy a significant volume. In the case of variable inclination continuous transvers stub (VICTS) antennas, each rotating component typically includes a separate bearing that requires mounting features and additional volume. This results in a less efficient antenna for a given volume.